1. Field of the Invention
This invention relates to a recording and/or reproducing apparatus of the kind arranged to record information on a flexible disc-shaped record-bearing medium in concentric or helical recording tracks, or to reproduce the record information from the record-bearing medium by means of a recording and/or reproducing head.
2. Description of the Prior Art
With regard to a recording and/or reproducing apparatus of the kind arranged to record or reproduce information by a recording and/or reproducing head on or from a flexible disc-shaped record-bearing medium such as a flexible magnetic disc-shaped sheet with the information recorded in a state of either concentric or helical recording tracks on the medium, many and varied methods have been contrived and proposed for keeping the head in a satisfactorily and stable confronted state with the magnetic sheet. The term "confronted state" as used herein for the purpose of this invention means a state of the head being either in contact or not in contact with the magnetic sheet.
In cases where the magnetic sheet is of a small diameter, it is nearly impossible to utilize an air flow which arises from the rotation of the magnetic sheet for stabilization thereof as in the case of the magnetic sheet of a relatively large diameter. In the case of the small diameter magnetic sheet, therefore, the confronted state between the sheet and the head must be stabilized by some other means. To meet this requirement, it is conceivable to have the magnetic sheet pushed against the recording and/or reproducing head by means of a pushing pad in the same manner as generally employed for a floppy disc device. In the event of a relatively thin magnetic sheet (30 to 40 .mu.m), however, this method causes the magnetic sheet to be warped by the pushing pad. Further, the magnetic sheet might be damaged in case of high speed rotation of the magnetic sheet.
To solve this problem, there has been proposed a method for obtaining a stable confronted state between the head and the sheet, in which a head is confronted with the recording surface of a relatively thin magnetic sheet of a small diameter and a stabilizing plate is arranged on the reverse side of the magnetic sheet to closely confront the head through the sheet in such a way as to stabilize the magnetic sheet relative to the head. In this case, the stabilizing plate is provided with an escape groove for avoiding collision with the head. The head is arranged in a position corresponding to this escape groove of the stabilizing plate and to protrude somewhat further than the rotating surface of the magnetic sheet toward the stabilizing plate.
In accordance with this method, if the magnetic sheet is left in a stationary state or a non-rotating state over a long period of time under the above-stated condition, the magnetic sheet might come to have plastic deformation. Such deformation of the sheet makes satisfactory recording and reproducing operations nearly impossible.